1. Field of the Invention
The present invention relates to seats mounted in vehicles and, more particularly, to a vehicle seat having a foldable headrest.
2. Description of the Related Art
To efficiently utilize the space inside the passenger compartment of a vehicle, a vehicle seat, in which a headrest mounted to the upper end of a seat back can be folded onto the front of the seat back and the seat back can be folded such that the seat back is folded onto a seat cushion, is proposed and used. A vehicle seat, having the above-mentioned construction, allows a person to fold the seat back and/or the headrest and load large objects into the passenger compartment, thus efficiently utilizing the space inside the passenger compartment.
Meanwhile, in the vehicle seat of the above-mentioned construction, even if the headrest is folded onto the front of the seat back, it is possible for a passenger to sit on the seat cushion. However, when the headrest is folded onto the front of the seat back, the passenger cannot comfortably sit on the seat cushion. Japanese Patent Application Publication No. 2005-73833 (JP-A-2005-73833) describes a method of informing passengers of an uncomfortable seat state using a warning system operated alarm, etc., when the headrest is folded onto the seat back.
However, even though the warning system informs passengers of the uncomfortable seat state, a passenger may ignore the warning signal and sit on the seat cushion, and thus there is room to improve this method.